Such an epicyclic gear train generally consists of three basic components, namely a sun gear on a central shaft, a ring gear concentrically surrounding the sun gear, and a carrier for one or more planet pinions in mesh with the sun and ring gears. By selectively coupling these three components to a drive shaft, a load shaft and a brake, different speed ratios can be established between the drive and load shafts.
In order to avoid eccentric stresses, it is generally desirable to mount at least two and preferably three or four planet pinions on the carrier in a symmetrical manner, advantageously with the aid of stub shafts which are fixedly secured to the carrier and on which the pinions are freely rotatable. A convenient support for these stub shafts comprises a pair of parallel disks forming part of the carrier body, the disks being provided with pairs of mutually aligned mounting holes for the shaft ends. The disks usually consist of sheet metal and are permanently secured to each other, as by welding, with just enough spacing to receive the planet pinions. In order to fix the stub shafts in position upon completion of the assembly, incisions may be cut on a milling machine into the peripheries of the preformed mounting holes whereupon the ends of the inserted shafts may be deformed by peening so that portions thereof are extruded into these incisions to secure the shaft against rotation. The formation of the incisions in a separate milling operation is, however, cumbersome and expensive.